Seal arrangement for compressor or turbine section of gas turbine engine

Abstract

A seal arrangement for a gas turbine engine comprises a rotor hub. A a stator portion projects toward the rotor hub, an annular gap formed between the rotor hub and an end of the stator portion. A leakage path is defined from a first cavity on a first side of the stator portion, through the annular gap, and to a second cavity on a second side of the stator portion by positive pressure differential from the first cavity to the second cavity when in operation. A dynamic seal is secured to the rotor hub, the dynamic seal having geometrical features positioned relative to the annular gap to induce a flow of gas through the annular gap from the second cavity to the first cavity when in operation and rotating with the rotor hub.

What is claimed is: 
     
         1 . A seal arrangement for a gas turbine engine comprising:
 a rotor hub;   a stator portion projecting toward the rotor hub, an annular gap formed between the rotor hub and an end of the stator portion, a leakage path being defined from a first cavity on a first side of the stator portion, through the annular gap, and to a second cavity on a second side of the stator portion by positive pressure differential from the first cavity to the second cavity when in operation; and   a dynamic seal secured to the rotor hub, the dynamic seal having geometrical features positioned relative to the annular gap to induce a flow of gas through the annular gap from the second cavity to the first cavity when in operation and rotating with the rotor hub.   
     
     
         2 . The seal arrangement according to  claim 1 , wherein the geometrical features of the dynamic seal are airfoils circumferentially distributed on and projecting from a surface of the rotor hub. 
     
     
         3 . The seal arrangement according to  claim 2 , wherein the airfoils have a concave pressure surface and a convex suction surface. 
     
     
         4 . The seal arrangement according to  claim 2 , wherein the airfoils have straight surfaces from leading edge to trailing edge, with a width of passages between adjacent pairs of the airfoils being greater at the trailing edge than at the leading edge. 
     
     
         5 . The seal arrangement according to  claim 2 , wherein the airfoils are on a base ring secured to the rotor hub. 
     
     
         6 . A gas turbine engine of the type having at least one of a turbine section and a compressor section defined by a rotor hub, a stator portion projecting toward the rotor hub, an annular gap formed between the rotor hub and an end of the stator portion, a leakage path being defined from a first cavity on a first side of the stator portion, through the annular gap, and to a second cavity on a second side of the stator portion by positive pressure differential from the first cavity to the second cavity when in operation, the gas turbine engine comprising:
 a dynamic seal secured to the rotor hub, the dynamic seal having geometrical features positioned relative to the annular gap opposite the end of the stator portion.   
     
     
         7 . The gas turbine engine according to  claim 6 , wherein the geometrical features of the dynamic seal are airfoils circumferentially distributed on and projecting from a surface of the rotor hub. 
     
     
         8 . The gas turbine engine according to  claim 7 , wherein the airfoils have a concave pressure surface and a convex suction surface. 
     
     
         9 . The gas turbine engine according to  claim 7 , wherein the airfoils have straight surfaces from leading edge to trailing edge, with a width of passages between adjacent pairs of the airfoils being greater at the trailing edge than at the leading edge. 
     
     
         10 . The gas turbine engine according to  claim 7 , wherein the airfoils are on a base ring secured to the rotor hub. 
     
     
         11 . A method for sealing a leakage path in a gas turbine engine, the leakage path being defined from a first cavity on a first side of a stator portion, through an annular gap, and to a second cavity on a second side of the stator portion, the method comprising:
 receiving gas in the first cavity during operation of the gas turbine engine, such that a pressure in the first cavity is greater than a pressure in the second cavity; and   inducing a flow of gas with a dynamic seal from the second cavity, through the annular gap, to the first cavity, by rotation of the rotor hub.   
     
     
         12 . The method according to  claim 11 , wherein inducing the flow of gas comprises rotating airfoils of the dynamic seal with the rotor hub.